This is the mail archive of the
cygwin
mailing list for the Cygwin project.
Re: questions about DLL's: .a, .def, and .dll
Igor Pechtchanski <pechtcha <at> cs.nyu.edu> writes:
> On Fri, 27 Aug 2004, Oliver wrote:
>
> > creating a .a file, a .def file, and a .dll file, yet I can
> > build a program that links to, e.g., mylib.dll, with only "-L. -lmylib",
> > *wihtout* having the .def or .a available. So where and when are the .a and
> > .def files needed?
>
> The newer versions of gcc apparently allow you to link directly to a .dll
> file. The .def and .a are needed for older versions of gcc, and possibly
> for some other tools.
I guess the .def file might be used if you created your dll in cygwin/mingw but
are creating your program with VC++ and linking to your non-VC++ dll. (?)
> ...a DLL built with C++ symbols won't be usable from
> other applications that try to call those functions. The reason you want
> it for DllMain is that the Windows loader will be looking for the unmunged
> name "DllMain". Are you sure that it's really invoked when the DLL is
Yes. I even tried it on the latest dllhelpers C++ example: just renamed
dllinit.c to .cc and changed makeit.bat to use g++ instead of gcc, and
everything still works. Perhaps g++ "knows" to leave DllMain alone? Or perhaps
the APIENTRY macro that appears just in front of DllMain prevents munging?
Oliver
--
Unsubscribe info: http://cygwin.com/ml/#unsubscribe-simple
Problem reports: http://cygwin.com/problems.html
Documentation: http://cygwin.com/docs.html
FAQ: http://cygwin.com/faq/